Tubular members for erecting a variety of structures range from bridges, airplane frames, railings, boats, bicycle, motorcycle and automobile frames, wheelchairs, and even erector sets (toys) are known for decades. One practical aspect of these structures are the critical choice of connectors that fix and hold the juxtaposition of one tubular member relative to another.
The tubular structure itself is not any more sturdy than its weakest link, mainly, the connector assembly being used. As a result, complex and costly fabricated connectors are often required which, if properly installed, ensure the reliability of the erected framework over time.
A cleating device involving a flexible clamp for a cylindrical cable is disclosed in U.S. Pat. No. 5,482,234 (Jan. 9, 1996 to one R. C. Lyon). A device serving as a cross-connector for two crossing tubular members is described in U.S. Pat. No. 4,817,897 (Apr. 4, 1989 to one Ulrich Kreusel). Other relevant teachings are Brooks U.S. Pat. No. 575,631 (1997), Hefner U.S. Pat. No. 2,872,141 (February, 1959); and Kahler U.S. Pat. No. 1,046,600 (1912).
Available connectors are often only adapted to provide right angle joining or connection between tubular members lacking any angular options, as are sometimes required. Available connectors lack the versatility to connect other non-(cylindrical) tubular, shared accessories. Available connectors also offer no means of adjustment lengthwise down a tube and around its circumference. Currently, available connectors provide no accurate self-realignment property to provide flush mating surfaces for the connecting nut and bolt heads as well as flush mounting of accessories. Also, being somewhat complex to assure sturdiness, they are costly to use, thusly may limit the applications where tubular members could provide an extensive support structure.